This threaded inline swivel relates in general to means for connecting coaxial hoses, fittings, and nozzles used by motorists for fuel dispensing at a service station, and more specifically to improvements within the swivel allowing for concentric rotation of hoses, nozzles, and fittings connected thereto without leakage of fuel therefrom. A unique aspect of the present swivel is a male nut that constricts its inner diameter so that it fits within a female nut with reduced disruption to fuel flow. This invention is especially useful when applied in a fuel line at its connection to a nozzle where the nozzle may turn axially relative to the hose.
Upon arriving at a pump of a service station, a motorist views a nozzle connected to a length of hose, and the hose connected to the pump. The lengths of hose, fittings, and nozzles require connection among themselves and to service station pumping facilities. Hoses extend from fixed and rigid piping extending from the pump, generally concealed from a motorist. The hoses may extend from the side of the pump, approximately midway on its height or from overhead of the pump, descending to the typical usage height of a motorist. Hoses, manufactured to specific lengths, generally extend continuously from the pump to the nozzle. However, hoses, fittings, and nozzles interconnect in a generally linear path for conveying fuel from the pump to the motorist's fuel tank. At a service station, the nozzle enters the motorist's fuel tank at one angle while the hose extends from the pump at a different angle. Though hoses and select fittings can twist to a degree and accommodate the difference in angles, in time hoses wear from such twisting. Where a hose connects to a rigid fitting, the fitting may not tolerate such a change in angles through the hose to it.
Further, numerous swivels in the prior art furnish rotation between connected hoses and fittings, and more particularly, such swivels normally see use in lines containing fuel. Generally swivels have use in those situations where the fuel line leads from a fuel dispenser to a nozzle.
Swivels also encounter forces imposed upon them by the service station environment, often errant motorists. Swivels may endure unbalanced internal forces as in a nuisance break or drive off. In such a nuisance break, greater fluid forces are exerted in one direction upon one part of the swivel than upon the other. When spontaneous and unbalanced high pressures are encountered, the pressure exerted upon one component of the swivel in one direction, substantially differs from the fluid pressure that may be exerted upon the other components of the swivel, and therefore, this pressure disparity tends to increase the risk of premature separation or failure of a swivel, in an untimely and dangerous fashion. This can and has occurred particularly where the fluid pressure in the hose may undergo a phenomenon that is equivalent to “water hammer.”
The lengths of hose, fittings, and nozzles require connection among themselves and to service station pumping facilities. Hoses, fittings, and nozzles have swivels, often near the pump, that rotate when an errant motorist drives away with a hose in a vehicle, and thus prevent a spill or worse a fiery catastrophe. Until such an event, a swivel joins two sections of a fueling line or fittings and permits passage of fuel therethrough. As fuel pumps through the flow line, pressure spikes significantly and substantially throughout the hose, momentarily, and even at the location of a swivel, as when the flow is suddenly stopped, as for example, by the automatic shutoff by a nozzle when the fuel tank is full. Hence, leakage at such couplers has frequently occurred in the field, and on occasion, as previously explained, untimely separation or damage of the swivel has happened.
Also, where a hose connects to a nozzle or to a fitting, a swivel joins the two adjacent components for continuous flow there through while allowing for coaxial rotation.